1. Field of the Invention
This invention relates to a recording medium which exploits the removal by vaporization, the deformation, etc. of a recording thin film as effected by the use of heat from a recording beam such as laser beam and/or heat generated indirectly through auxiliary means.
2. Description of the Prior Art
Heretofore, as the recording thin film of the type described above, an embodiments employing paraffin, oil or the like has been known. This technique performs the display, storage, transfer etc. of an image by projecting infrared light onto the recording thin film of paraffin or the like and by utilizing the deformation of the thin film based on the effect of vaporization and/or the effect of diffusion to the circumference. To the end of improving the disadvantages of this aspect, for example, the disadvantage that the image of paraffin or the like is prone to naturally disappear on account of the remaining heat after the projection of light, a proposal as described below has also been made. A substance which absorbs the light to-be-projected well is arranged on a predetermined substrate, and heat which is generated by the light having been absorbed by the substance is given to the recording film so as to cause the deformation of the recording film based on vaporization and movement. Even when the layer of the substance to absorb the projected light is made as a thin layer, the light absorption is sufficiently great. Accordingly, the supply of the heat to the recording film proceeds efficiently, and the natural disappearance of the image after the projection as above described hardly occurs. That is, the image can be satisfactorily stored. As the substances which absorb the projected light, there are employed CdS, CdSe, As.sub.2 S.sub.3 etc. The recording media of this type are disclosed in the official gazette of Japanese Patent Application No. 48-142442.
It is the present situation, however, that such recording media have not yet been put into practical use because the recording sensitivity and the readout error rate (signal-to-noise ratio) thereof are not satisfactory in practical use.
Presently there is a demand to adopt a semiconductor laser device as a recording beam source for the recording media of the specified type.
Prior art is described in the following literature:
(1) S. Kobayashi and K. Kurihara; Appl. Phys. Letters 19 (1971), p. 482
(2) M. Terao; Proceedings of the 6th Conference on Solid State Devices, Tokyo, 1974, Supplement to the Journal of the Japan Society of Applied Physics, vol. 44, 1975, pp. 79-84.